efficacy of a transcranial vibrating system for minimizing dizziness during caloric testing

Conditions: Vestibular Function Tests; Dizziness

Summary: vestibular disorders are among the most common causes of disability in society. vestibular dysfunction affects over one third of the population over the age of 40 and a significant percentage of the younger population. vestibular disorders have a dramatic impact on daily life impacting work, relationships, and even activities of daily living. diagnosis of vestibular disorders is often facilitated by functional vestibular tests. the most common of these tests is videonystagmography, during a critical portion of which, the "caloric test," warm and cool stimuli are presented in the outer ears to stimulate the inner ear vestibular system. the vertigo produced by caloric stimulation not uncommonly results in nausea, and sometimes vomiting, sometimes to the point of not being able to complete the test protocol. in this project we examine a device that has shown promise and might be beneficial for improving the testing for vestibular disorders. we hypothesize that with this device, the nausea associated with caloric testing will be significantly reduced when the device is used, while it will not change the results of the test in a statistically significantly manner. to date, the device has only been systematically tested on healthy volunteers.

vestibular disorders can be difficult to diagnose and can vary in symptoms and fluctuate in severity. it is typically hard to determine which vestibular system (left/right) might be causing the vestibular disorder, as both sides normally work in unison. testing the vestibular function in each side (left/right) of a patient is typically done with "caloric testing", which allows testing the left and right vestibular systems separately. however, it leads to nausea in most patients, and part of the clinical test is spent waiting for the patient to recover. many patients undergoing caloric testing experience nausea to the point that some patients cannot complete the test, while others need a long period of time to recover from the nausea and dizziness induced by the testing. while it is hoped that this project will ultimately help establish the effectiveness of the transcranial vibration system for a range of vestibular disorders, we choose caloric testing for an initial assessment because it is performed daily in the clinic, it is easy to administer, and there is very little controversy about its use. specific aims: using otolith labs' device, we wish: 1. to determine if subjects undergoing caloric testing treated with the device 1. experience less nausea than with no device, or 2. if the subjects do experience nausea, whether the time to resolution is shorter with the device than with no device. 2. to determine if the clinical results obtained by caloric testing are significantly different with the device compared to not wearing the device. objectives: primary: to demonstrate the efficacy of a bone conduction device at preventing nausea in subjects undergoing vestibular (particularly caloric) testing, as measured by the reduction from baseline of symptoms associated with (caloric)-testing secondary: to show that the use of the bone conduction device does not change the clinical measures obtained by vestibular caloric testing.

Eligibility criteria:
inclusion criteria: 1. subject can speak and comprehend english. 2. subject can stand a strap placed on their head for an hour. exclusion criteria: 1. history of head injury within the last six months 2. presence of severe aphasia 3. history of diagnosed neuropsychiatric disorders 4. documented neurodegenerative disorders 5. pregnancy \[female candidates will be asked if they are pregnant\] 6. history of cerebrovascular disorders 7. history of ear operation other than myringotomy and tube placement in the past

Keywords: caloric testing vestibular nystagmography vng videonystagmography